Update calibration.md

doc/calibration.md

@@ -11,7 +11,7 @@ In practice, the calibration structure could be assembled using any 4 boxes, siz
 
 ## Assembling the Calibration Structure 
 
-Since the proposed calibration structure does not require markers, users should only pay attention in placing the boxes, one on top of each other following a 90^o^ rotational pattern, as depicted in the following pictures. Snapping is performed using each respective bottom boxes sides.
+Since the proposed calibration structure does not require markers, users should only pay attention in placing the boxes, one on top of each other following a 90<sup>o</sup> rotational pattern, as depicted in the following pictures. Snapping is performed using each respective bottom boxes sides.
 The first image shows the assembling procedure from a diagonal perspective. For more descriptive design we use color-coded representation. The first (bottom-most) box is colored in red, the second in green, the third in blue while the last (top-most) is depicted in yellow. 
 ![Calibration Assembling (Diagonal-View](https://github.com/VCL3D/VolumetricCapture/raw/master/doc/StructureGuideTextureColored.png)
 
@@ -30,7 +30,7 @@ And this last image depicts the corresponding calibration procedure from the top
 
 The formerly placed calibration structure acts as the global coordinate system anchor. 
 - The setup requires all 4 Intel RealSense sensors to be placed __perimetrically around the calibration structure and looking inwards (i.e., towards the structure)__. 
-- In order to capture the desired object in full-360^o^, sensors should be placed approximately at __90^o^ intervals__,
+- In order to capture the desired object in full-360<sup>o</sup>, sensors should be placed approximately at __90^o^ intervals__,
 - Importantly, towards achieving better performance during the graph-based refinement step, sensors should be positioned diagonally, which means that __planar sides of the structure look in-between two adjacent sensors__.
 - All viewpoints should target the middle of the structure in a way that the __structure is depicted at the center of the received images__ both horizontally and vertically. 
 - Considering the specific field-of-view of the Intel RealSense and with a view to capturing a standing person at the center of the capturing space, all sensors must be positioned at a __distance from the structure ranging from 1.75 to 2.2 meters__.